Film developing reel



Nov. 25, 1952 F. E. BAFTHOLY FILM DEVELOPINGIREEL 3 Sheets-Sheet 1 Filed Oct. 5, 1949 INVENTOR FREDERICK BARTHOLY B) sk ww ATTORNEYS Ndv. 25, 1952 F. E. BARTHOLY 2,619,300

FILM DEVELOPING REEL Filed Oct. 5, 1949 3 Sheets-Sheet 2 INV TOR FREDERICK E. BARTH Y %EYS Nov. 25, 1952 F. E. BARTHOLY 2,619,3

FILM DEVELOPING REEL Fi led Oct. 5, 1949 s Sheets-Sheet s 'nuuuclnunu I .J/F I o I o I 0 135 o l 0 o uucmuuuEBL 3O 3/ FE]. 9

INVENTOR FREDERICK E. BAPTHOLV yS M ATTORNEYS Patented Nov. 25, 1952 FILM DEVELOPING REEL Frederick E. Bartholy, Vestal, N. Y., assignor to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware Application October 5, 1949, Serial No. 119,633

3 Claims.

This invention relates to developing reels for photographic film, and more particularly to reels used in daylight developing tanks which must be loaded in total darkness.

Developing reels for rollfilm are widely used for daylight developing in connection with a lighttight developing tank which accommodates the reel. The tank is provided with a cover having a light-excluding inlet through which the required developing or fixing solution is poured in, and the reel can be rotated in order to agitate the liquid.

Conventional reels comprise essentially two disk-shaped flanges mounted upon and spaced by a central member or shaft. The disks are provided with spiral passageways in the form of grooves or channels parallel to each other for accommodating the edges of the film strip during the winding operation, and maintaining adjacent convolutions properly spaced during the developing process. The two disks are generally displaceable longitudinally over the shaft in order to accommodate various standard film sizes.

The film feeding into these reels is a difiicult procedure, inasmuch as the spiral grooves offer considerable frictional resistance, and, since the film is fed from the outer periphery of the disks inwardly toward the central member, the threading end of the film is inaccessible. Hence, the film has to be pushed in from the outside to follow the spiral convolutions. The progressively decreasing diameter of the groove bends the film into sharper curves, which, due to the expanding resiliency of the film, increases the frictional resistance as it nears the central portion of the reel. This operation, difficult even under favorable lighting conditions, must be performed in total darkness with the result that the full length of the film can seldom be threaded and the emulsion surface is often damaged by handling.

A marked improvement in these reels has been disclosed in application Serial No. 6,938, filed February '7, 1948, in the name of Frederick M. Siedenburg, which consists in permitting a certain rotary displacement of one disk with respect to the other, and provides each disk near the entrance to the spiral groove with a latch or detent mechanism. The latter, by its physical structure, acts as a film gripping means in one direction of rotary movement of the disk, whereas, in the opposite direction of movement it releases the gripping action. When one disk is rotatable with respect to the other, relatively speaking, both disks are movable and act in tandem. In the disk moved in one direction the detent grips the film, whereas in the other disk, the detent permits pas- 2 sage of the film and vice versa. In this manner, the film is pushed into the grooves at each direction of rotary movement by one or the other detents.

While a reel of the above type is eminently satisfactory, it is, of course, costlier to produce because the detent mechanisms, even in their simplest form such as a ball and spring, require assembly operations. This also entails finishing operations after molding, to clear the flash residue of the plastic material in the narrow space which houses the detents. Emulsion particles and other foreign substances are also easily accumulated in the narrow confines of the space housing the detents, causing clogging which will prevent gripping action.

The present invention proposes to employ the rotating disk type of film feed, but eliminates detents or latch mechanisms in any form. A reel made in accordance with the present invention requires no additional assembly operations, inasmuch as the film feed mechanism is molded in and is an integral part of the reel. In other words, after the two parts of the reel leave the mold and are joined together, the reel is ready for operation and will feed a length of film by back and forth rotation of one of the disk-shaped flanges.

The primary object of the present invention is to provide a film developing reel which is simple in construction, easy to produce in large quantities, and insures automatic feed of a full length of film.

It is a particular feature of this invention that the film inserted in the reel is pulled into the spiral guiding channel at each reciprocating rotary motion of the reel flanges by means of a simple film clip.

Another feature of this invention is that in a modified form, particularly for films of narrow width, use is made of the resilient property of the film base to perform the function of the film clip.

A particular advantage of reels constructed in accordance with this invention resides in the ease of handling in total darkness and ability to feed a full length of standard size of film in either a dry or wet state.

Another advantage in the use of a feeding clip in conjunction with the reel is that not only film material, but paper, canvas or any flexible material which may be sensitized for photographic use, can be inserted and fed into the reel.

Other objects, advantages and features will be apparent from'the following description of the invention, pointed out in particularity in the ap- 3 pended claims, nd taken in connection with the accompanying drawing, in which:

Figures 1 and 2 are top and side views respectively, of one part of the reel;

Figures 3 and 4 are similar views of the other part;

Figure 5 shows the two parts assembled ready for use;

Figure 6 is an enlarged sectional view of a portion of the reel along lines 6-6 of Figure 2 illustrating also the turned-back leading edge of an inserted film strip;

Figure '7 is an elevational view in section of Figure 6 taken along lines 1--1;

Figure 8 is a side elevational view of the film clip with a length of film inserted;

Figure 9 is a to view of the film clip; and

Figure 10 is an enlarged sectional view of a portion, similar to Figure 6, showing the film clip in feed position.

The reel, according to this invention, consists essentially of a pair of disk members which have axially extending walls defining a narrow spiral V groove opposite to each other and adapted to hold, as well as guide, the longitudinal edges of strip material, such as photographic film, to be fed thereinto. A cone is provided over which the disk members are spaced and angularly displaceable, and strip material holding means are distributed over one wall of said groove. Means are provided for pulling the material into the groove including means at the leading end of the material which cooperates with certain of the holding means in the groove upon alternate relative angular displacement of the disk members.

Now referring to Figures 1 and 2, illustrating a portion of the complete reel assembly, they comprise a disk or flange ll having a spiral passageway in the form of a groove [2 formed integrally therewith by a thin slightly tapered wall I3 at right angles to the disk surface for insertion and guiding of the film through the ingress opening 14. One inner, and preferably the outer peripheral, side of the wall I3 is serrated, and these serrations are preferably of a saw-tooth shape as seen in the enlarged view of Figure 6. The sloping face of the serration should be toward the peripheral end of the spiral groove. In Figures 1 and 3, only a portion of a few convolutions of the groove is shown serrated for the sake of simplicity in illustration. It is to be understood that these ratchet serrations of the wall [3 run from the ingress opening 14 to the centrally located end of the groove. This construction is very simply attained by having the die or mold, from which the plastic spool is made, prepared with the ratchet like edge of the spiral grooves. In this manner, each disk comes out of the mold in the required shape and form. No other manufacturing operation will be necessary thereafter.

The disk II has a central tubular extension 16 provided with a longitudinal guide-groove H, the purpose of which will be discussed later. The extension I6 has a plurality of transverse grooves l8 spaced from each other in accordance with the width of standard film sizes.

The complementary portion of the reel, as shown in Figures 3 and 4, consists of a disk or flange H similar in construction to the one described above. The spiral groove I2 has a wall 13 with serrations running in complementary manner to that of the groove wall in the disk II. There is also an ingress opening [4 for the film. The central extension of the disk II is a short sleeve [9 having an inner diameter adapted to slip over the shaft 16 of the disk II as seen in Figure 5. The extensions of the disks thereby form a telescoping core of the reel. A number of longitudinal slots 20 are made in the sleeve [9 to secure a certain degree of resiliency and insure frictional engagement between the sleeve 19 and the tube l6, while a circular collar 2| may be engaged with the various grooves 18 to lock the two parts together at certain distances to accommodate different film sizes. The sleeve i9 has a longitudinal key 23 projected from its inner surface and adapted to engage the guide-groove ll of the tube IS. The width of this guide-groove determines the extent of the angular displacement of the disk H since the rotation thereof is checked by the key 23 against one or the other walls of the guide-groove ll. Both disks have a number of perforations 24 and 24 respectively, in the bottom of the spiral grooves l2 and [2' to permit access for the developing or other liquids to the film.

To facilitate the insertion of a film strip, the ingress openings I4 and [4 have tapered edges from the outer to the inner surface, terminating in the spiral groove as shown in the drawing. In this manner, the film may be inserted easily in complete darkness. There is also a lobe 25 and 25 respectively, on the rim of each disk near the ingress opening to facilitate locating the entrance and also to determine the parallel alignment of the disks.

When using the reel, the two disks are joined as seen in Figure 5 and spaced on the central tubular extension 16 so that collar 2| engages one of the grooves l8, whereby the space between the two disks is suitable for the particular size of film used. The disks are rotated with respect to each other until the entrance openings in each are in opposite parallel relation, which can easily be determined by feeling the two lobes 25 and 25' thereof. The key 23 in the upper portion, and the groove I! in the lower portion, are preferably so located in designing the reel that at one extreme position of rotary displacement the entrance openings are parallel.

Two modes of operation are feasible with the reel of the present invention. The preferred mode, suitable for all film sizes as well as other sensitized material besides film, includes the use of a feeding clip as illustrated in Figure 8. The alternative mode dispenses with the clip and feeds the film directly into the spaced guiding channels which the parallel spiral grooves form. This mode of operation is illustrated in Figure 6 and will be explained before discussing the film clip and its use.

The forcible feeding of the film in the reel herein described is based on the ratchet and pawl principle. The serrated wall forms a ratchet along the entire spiral groove, and the pawl, cooperating therewith, is either part of a feeding clip or may be the film itself. In both cases, the pawl member fits into the interdental spaces of the serrations and permits only a unidirectional travel for the film toward the center of the reel.

For films of the popular 35 mm. size, the resilient property of the film base may be used advantageously to perform the function of the pawl, and, for this purpose, before inserting a film strip the leading edge is turned back about A; of an inch to form a hook which, acting as a pawl, will engage the serrations. The film is then pushed in until the hook snaps into at least the first ratchet. After that, holding the reel in one hand by gripping one of the disks, the other is rotated back and forth as far as the key 23 and groove I1 permit, and the film thereby threaded in automatically. The disk which turns in the direction against the hooked end of the film will pull the film into the groove while, at the same time, on the other disk the bent portion of the film will snap past the ratchet. In this operation, one disk pulls and the other rides past the bent portion of the film. This is alternately repeated so that the two disks act in tandem in feeding the film into the reel. The bent portion of the film is, in effect, the pawl of the ratchet.

The width of the spiral groove in each disk is so designed that it will permit the bent-back edge of the film to fit snugly. The wall of the groove opposite the ratchet face is made smooth so that the film may slide by easily. In-the enlarged sectional view of Figure 6 it is seen how in one of the disks, the bent-back film strip 28 fits into the groove l2, and how it engages the ratchet face of the groove wall. The sectional view in Figure 7, taken along lines of Figure 6, illustrates the slightly tapered wall of the groove and the bent portion of the film 28 therein. The extent of relative rotation of the disks is not critical and should be calculated to permit a convenient angular motion for the wrist of the user. About 60-120 is a practical displacement. Of course, the displacement must be less than 180 due to the spiral character of the grooves.

Film sizes wider than 35 mm. are not well adapted for feeding by means of bending back the leading end in view of the fact that the body of the film has the tendency to curve or bend in the direction transverse to its length, and thereby jump out of the grooves. Also, the area covered by the groove Wall is far less in proportion to the total width than in narrower films. Consequently, the preferred mode of operation is recommended as described hereafter.

Referring to Figures 8 and 9, a simple film clip is seen comprising a base 30 of resilient spring material, or suitable plastic material, having at one end an extendin portion SI of suitable spring material, such as Phosphor bronze which may be attached to the base 30 by means of small rivets 32. The base and the extended portion may also be made of one piece bent back in the form shown. The inner face of the base carries a clamp 33 having a rounded and upturned edge 34. The clamp 33 is shown attached to the base by rivets 35, by way of example, although any suitable means of attachment, such as spot welding, etc., can be used. A portion of the clamp under edge 34 is spaced from the base 30 to allow insertion of the end of the film 28. Sufficient force is developed by the clamp 33 to hold the film firmly against the pull exerted in feeding, but allows its forcible insertion under the clamp. It will be understood that other well-known means of attaching the film to the base 30 of the clip may as Well be employed.

The reel employs a particular feeding clip for each size of film. The difference between the various clips is only in the width of the base 30 and extended portion 31 so as to fit the distance between complementary grooves of the disk members as they are set to a particular film size.

Then the clip is attached to the film, it is inserted into the ingress opening Hi and H5 with the portion 3! turned toward the serrated or ratchet face of the groove. As seen in the enlarged view of Figure 10, the portion 3| becomes a ratchet pawl and feeding operation is simply effected by back and forth motion of one flange of the reel with respect to the other. In one direction of motion, one flange will ride past the springy ratchet 3| which, at the same time, abuts tightly against the ratchet of the other flange. The clip is thus propelled toward the inner terminating end of the groove, and the film is pulled past the serrated faces until the end of the spiral groove is reached.

The total length of the spiral groove is so dimensioned that a standard length of film is accommodated including the length of the feeding clip. The loaded reel may then be placed. in a suitable tank having a light-tight cover in the same manner as conventional reels. As mentioned before, the clip feed is also useful for material other than film, such as paper which cannot be fed into conventional reels, being far less resilient than film material, or for wet film which may have been subjected to washing prior to developing or fixing.

I claim:

1. A developing reel for photographic rollfllm comprising a pair of opposed disk members on a common axis having axially extending walls defining complementary spiral grooves opposite to each other adapted to hold and guide the film to be fed thereinto, said disks being relatively angularly displaceable, a plurality of radially extending ratchet-faced serrations distributed over one wall of said groove in each of said members, a feeding clip for pulling said film material into said groove including a clamp for attaching said clip to the leading end of said material and an extending portion for cooperating with said serrations progressively upon alternate relative angular displacement of said members.

2. A developing reel for photographic rollfilm comprising a pair of opposed disk members on a common axis having axially extending walls defining complementary spiral grooves opposite to each other adapted to hold and guide the film to be fed thereinto, said disks being relatively angularly displaceable, a plurality of radially extending ratchet-faced serrations distributed over one wall of said groove in each of said members, a feeding clip comprising a resilient base, a clamp afiixed to said base and adapted to hold film material tightly thereagainst, a spring of a width substantially equal to the space between walls forming the complementary grooves of said disk members, extending from one end of said base in the direction toward said clamp, said spring being adapted to abut against radial faces of said serrations and ride past the sloping faces thereof, whereby at relative, alternate, angular displacement, of the disks said spring is positioned between interdental spaces of said serrations and said clip is propelled toward the inner terminating end of said groove.

3. A developing reel for photographic rollfilm comprising a pair of opposed disk members on a common axis having axially extending walls defining complementary spiral grooves opposite to each other adapted to hold and guide the film to be fed thereinto, said disks being relatively angularly displaceable, a plurality of radially extending ratchet-faced serrations distributed over one wall of said groove in each of said members, a feeding clip comprising a resilient base, a clamp afiixed to said base and adapted to hold film material tightly thereagainst, a bent portion of said base having a width substantially equal to the space between walls forming the complementary grooves of said disk members, said portion extending from one end of said base divergently in the direction toward said clamp, and being adapted to abut against radial faces of said serrations and ride past the sloping faces thereof, whereby at relative, alternate, angular displacement of 5 REFERENCES CITED The following references are of record in the file of this patent:

Number Number UNITED STATES PATENTS Name Date Pless Mar. 29, 1938 Becker Feb. 25, 1941 FOREIGN PATENTS Country Date Germany Sept. 7, 1939 

